Rotary piston machine



Dec. 5, 1967 I w, KENNEDY 3,356,291

ROTARY PISTON MACHINE Filed Oct. 6, 1965 FIG. I 2

22 I00 96 I s 7, 44 24 FIG.5

United States Patent 3,356,291 ROTARY PISTON MACHINE Thomas W. Kennedy, 134 Wildwood Ave., Upper Montclair, NJ. 07043 Filed Oct. 6, 1965, Ser. No. 493,385 Claims. (Cl. 230-145) ABSTRACT OF THE DISCLOSURE A rotary machine for use as a combustion engine, pump or motor comprising: an outer body with a longitudinal axis having a peripheral wall and a pair of axiallyspaced end walls forming a cavity therebetween; an inner body disposed in said cavity forming a plurality of peripherally-spaced, variable-volume chambers therebetween and having an axis arranged parallel to said outer body axis; gear means engaging said inner body and said outer body for rotating said inner body about its axis; and shaft means mounted on said outer body coaxially therewith with a variable-offset eccentric portion on which said inner body is journaled coaxially therewith for revolving said inner body about said outer body axis and for varying the offset distance between said inner body axis and said outer body axis in a selective manner.

The present invention relates to a rotary piston machine and particularly to a rotary piston machine having a variable-offset shaft eccentric.

A prior-art rotary piston machine for use as a pump, a motor or a combustion engine, is described in US. Patents Nos. 724,994, 1,617,863, 1,636,486, 2,988,008 and 2,988,065. Said prior-art rotary piston machine includes an outer body having a cavity with an axis, a shaft extending through said outer body coaxially therewith, said shaft having an eccentric portion disposed in said cavity with an axis parallel to said shaft axis and offset at a fixed distance therefrom, and an inner body disposed in said cavity journaled on said eccentric coaxially therewith for planetary rotation relative to said outer body and for forming variable-volume chambers therebetween. Said outer body has an inner surface and said inner body has an outer surface facing said inner surface. One of said surfaces has a controlling profile of one or more lobes, the profile being either an epitrochoidal profile or an hypotrochoidal profile.

One problem with said prior-art rotary piston machine is that said controlling profile, which is either an epitrochoidal shape or hypotrochoidal shape, limits the chamber displacement ratio and the engine compression ratio, as fully explained in the aforementioned US. Patent No. 2,988,065.

In accordance with one embodiment of the present invention, the chamber displacement ratio and compression ratio can be improved substantially by using a varying-offset gear means and a varying-offset eccentric means, which generate a novel profile that is not as limiting as said epitrochoi-dal profile and said hypotrochoidal profile.

Accordingly, it is one object of the invention to provide a rotary machine having an inner body supported within an outer body for rotation relative thereto about an axis parallel to the axis of said outer body with a varying offset between the outer body axis and the inner body axis, the machine being a type in which either the inner body or the outer body rotates and the opposite body is stationary, or a type in which both the inner and the outer body rotate in the same direction.

It is another object of the invention to provide the aforementioned rotary machine according to the aforementioned object, which can also be used as an internal combustion engine.

It is still another object of the invention to provide a combustion engine according to the aforementioned objects having an outer body with an inner surface having a profile that is described by a line that is generated by a point on the inner surface of a circle rolling on the outer surface of a modified ellipse.

To the fulfillment of these and other objects, the invention provides a rotary machine comprising an outer body, an inner body, a gear means and a shaft with a variable-offset eccentric portion. Said outer body has a peripheral wall with a longitudinal axis and a pair of axially-spaced end walls forming a cavity therebetween. Said inner body is disposed in said cavity forming a plurality of peripherally-spaced, variable-volume chambers therebetween and having an axis arranged parallel to said outer body axis. Said gear mean engages said inner body and said outer body for rotating said inner body about its own axis. Said shaft is mounted on said outer body coaxially therewith. Said eccentric portion supports said inner body for revolving of said inner body about said outer body axis and for varying the offset distance between said inner body axis and said outer body axis in a selective manner.

Other objects of the invention will become apparent upon reading the annexed description. The following drawings, wherein like parts are designated by like numerals in the several views, include:

FIG. 1 is a sectional view of a rotaiy machine embodying features of the present invention;

FIG. 2 is a sectional View taken along the line 22 of FIG. 1;

FIG. 3 is a sectional view taken along the line 33 of FIG. 2;

FIG. 4 is a sectional view taken along of FIG. 2; and

FIG. 5 is a sectional view taken along the line 55 of FIG. 1.

Referring to FIG. 1, one embodiment of the present invention is a rotary machine or combustion engine 10. Engine 10 includes an outer body 12, an inner body 14 enclosed by outer body 12, a shaft 16 extending through outer body 12 with an eccentric portion or crank arm 18 on which inner body 14 is journaled, and a gear means 20 for rotation of inner body 14 relative to outer body 12.

Outer body 12 and shaft 16 are coaxial along a common outer body axis 22. Inner body 14 and eccentric 18 are coaxial along a common axis 24.

Outer body 12 has a peripheral wall 26 with a radiallyinner surface 28 and a pair of end walls 30, 32 with respective axially-inner faces 34, 36 which together form a cavity 38. End walls 30, 32 have respective wall bearings 40, 42, which are coaxial with each other along axis 22.

Inner body 14 has three apex portions 44, 46, 48 with respective apex seals 50, 52, 54, which engage radiallyinner surface 28 and which form three working chambers 56, 58, 60 therebetween. Inner body 14 has axially-outer sides 62, 64, which respectively face inner faces 34, 36. Outer sides 62, 64 have respective end seals 66, 68, which engage inner faces 34, 36 for gas and oil sealing.

Shaft 16 has axially-spaced portions 70, 72, which are respectively journaled in wall bearings 40, 42. Shaft 16 is coaxial with outer body 12 along axis 22.

Eccentric 18 has a peripheral wall 74 with a circular radially-outer surface 76, and has a rectangularly-shaped opening 78, which extends therethrough in an axial direction. Opening 78 has opposite lengthwise radially-inner bearing surfaces 80, 82 and has opposite short side radially-inner surfaces 84, 86. Eccentric 18 is coaxial with the line 44 inner body 14 along axis 24, which is parallel to shaft axis 22. Axis 24 is separated from axis 22 by a variable offset or distance 88, which varies in a selective manner with each revolution of eccentric 18 and shaft 16. Eccentric 18 also has an intermediate shaft portion 90 with a square crosssection, which is fixedly connected at its ends to shaft portions 70, 72 coaxially therewith.

Intermediate shaft portion 96 has a pair of radiallyouter bearing faces 92, 94, which respectively face surfaces 80, 82 and which form gaps 96, 98 therebetween. Gaps 96, 98 contain respective anti-friction means 160, 102, such as roller-type bearings. Intermediate shaft portion 9d also has a pair of radially-outer faces 104, 166, which face toward respective surfaces 84, 86. Eccentric 18 also has a compression spring means 108, such as a compression coil spring, which is disposed between surface 84 and face 164 urging said parts apart and tending to increase the size of offset 88. With this construction, eccentric 18 has a variable-offset type of eccentricity.

Gear means 20 includes a pair of axially-spaced gear units 110, 112. Gear unit 110 is identical to gear unit 112 and is described hereafter in detail.

Gear unit 110 includes a large circular gear 114 which has internal teeth and which is fixedly connected to inner body 12 coaxially therewith along axis 24. Gear unit 110 also has a smaller ellipse gear, which has external teeth and which preferably has a modified-elliptical outer profile. Ellipse gear 116 meshes with circular gear 114. Ellipse gear 116 has two-thirds the number of gear teeth as circular gear 114. Outer body 14 is preferably stationary, and shaft 16, eccentric 18 and inner body 14 rotate relative thereto in the same clockwise direction. Shaft 16 and eccentric 18 have a rotary speed, which is three times greater than the rotary speed of inner body 14.

With such construction, embodiment has a novel profile, which is the profile of inner surface 28, which is the travel path of the tips of apex seals 50, 52, 54, which has definite non-epitrochoidal mathematical characteristics, and which is generated by the rolling of circular gear 114 on ellipse gear 116. Thus, engine 10 has a relatively larger intake chamber and relatively smaller compression chamber with an improved displacement ratio and an improved compression ratio. Moreover, sharp changes in the curvature of said profile of surface 28 can be substantially avoided thereby improving gas sealing.

Circular gear 114 preferably has an adjacent ringshaped shoulder 118 with a circular radially-inner hearing surface 129. Ellipse gear 116 has a corresponding adjacent elliptical radially-outer bearing surface 122, which is in rolling contact with surface 120. With such construction, eccentric shear loads, Which are directed in a radially-inward direction, pass through shoulder 118 and surfaces 120, 122 from inner body 14 to outer body 12 thereby minimizing shear load on gears 114, 116. However, tangential torque loads pass directly through gears 114, 116 from inner body 14 to outer body 12 for torquing shaft 16.

Gear unit 112 also has an identical internal circular gear 124 and an ellipse gear 126. Gear 124 has an identical shoulder 128 with a radially-inner bearing surface 130, and gear 126 has an identical radially-outer bearing surface 132. With such construction, shear loads acting on inner body 14 are balanced and resisted by equal reactions from gear units 110, 112.

In summary, this invention provides a rotary machine comprising an outer body and an inner body disposed therein for rotation relative thereto, in which either the inner body or the outer body can be the rotating body, or in which both the inner body and outer body can be rotating bodies, in which said machine can be used as an internal combustion engine, and in which the outer body of the machine has an inner surface with a novel profile of the type generated by a point on the surface of a circle rolling on the surface of a modified ellipse.

While the present invention has been described in a preferred embodiment, it will be obvious to those skilled in the art that various modifications can be made therein within the scope of the invention. It is intended that the appended claims cover all such modifications.

What is claimed is:

1. A rotary machine for use as a combustion engine, pump or motor comprising:

an outer body with a longitudinal axis having a peripheral wall and a pair of axially-spaced end walls forming a cavity therebetween;

an inner body disposed in said cavity forming a plurality of peripherally-spaced, variable-volume chambers therebetween and having an axis arranged parallel to said outer body axis; gear means engaging said inner body and said outer body for rotating said inner body about its axis; and

shaft means mounted on said outer body coaxially therewith a variable-offset eccentric portion on which said inner body is journaled coaxially therewith for revolving said inner body about said outcr body axis and for varying the offset distance between said inner body axis and said outer body axis and in which said outer body peripheral wall has a radially inner surface having a profile which is substantially a modified epitrochoidal curve, said curve being defined as the locus of a point in the plane of a circle which rolls without slipping on an ellipse in such a way that the planes of the circle and ellipse meet under constant angle.

2. A rotary machine for use as a combustion engine, pump or motor comprising; an outer body with a longitudinal axis having a peripheral wall and a pair of axiallyspaced end walls forming a cavity therebetween; an inner body disposed in said cavity forming a plurality of peripherally-spaced, variable-volume chambers therebetween and having an axis arranged parallel to said outer body axis; gear means engaging said inner body and said outer body for rotating said inner body about its axis; and shaft means mounted on said outer body coaxially therewith With a variable-offset eccentric portion on which said inner body is journaled coaxially therewith for revolving said inner body about said outer body axis and for varying the offset distance between said inner body axis and said outer body axis in a selective manner, in which said gear means includes at least one gear unit comprising:

an internal gear with a circular shape fixedly connecting to said inner body coaxially therewith; and an external gear with a modified-elliptical shape fixedly connecting to said outer body coaxially therewith for varying the offset between said inner body and said outer body and for rotating said inner body relative to said outer body.

3. A rotary machine for use as a combustion engine, pump or motor comprising: an outer body with a longitudinal axis having a peripheral wall and a pair of axiallyspaced end walls forming a cavity therebetween; an inner body disposed in said cavity forming a purality of peripherally-spaced, variable-volume chambers therebetween and having an axis arranged parallel to said outer body axis; gear means engaging said inner body and said outer body for rotating said inner body about its axis; and shaft means mounted on said outer body coaxially therewith with a variable-offset eccentric portion on which said inner body is journaled coaxially therewith for revolving said inner body about said outer body axis and for varying the offset distance between said inner body axis and said outer body axis in a selective manner, in which:

said inner body has a shoulder portion disposed adjacent to said gear means with a radially-inner bearing surface of circular shape; and

said outer body has a portion disposed adjacent to said gear means with a radially-outer bearing surface of modified-elliptical shape and in rolling contact with said radially-inner bearing surface for minimizing loading on said gear means.

4. A rotary machine comprising:

an outer body having a peripheral wall with a longitudinal axis and a pair of axially-spaced end walls forming a cavity therebetween;

a shaft coaxial with said outer body along said outer body axis mounted in said end walls and extending through said cavity for rotation relative to said outer body;

a shaft eccentric portion mounted on said shaft for rotation together therewith relative to said outer body With an eccentric axis disposed parallel to said outer body axis and separated therefrom by an offset distance, said eccentric having means substantially varying said offset distance in a selective manner with each revolution of said eccentric axis about said outer body axis;

an inner body journaled on said eccentric portion coaxially therewith and disposed in said cavity for rotation about said outer body axis relative to said outer body and forming a plurality of peripherally-spaced, variable-volume chambers therebetween; and

gear means interconnecting said inner body and said outer body for rotation of said inner body about said eccentric axis relative to said eccentric at a fixed speed ratio, said gear means comprising a circular gear, and an ellipitic-al gear which meshes with said circular gear, and in which one of said gears is fixedly connected to the inner body and the other said gear is fixedly connected to the outer body.

5. A rotary engine comprising:

an outer body with an axis having a peripheral Wall with a radially-inner surface and a pair of axiallyspaced end walls with axially-inner faces forming a cavity, said end walls having wall bearings;

an inner body with an axis disposed in said cavity and having a plurality of apex portions with respective apex seals engaging said radially-inner surface forming a plurality of working chambers therebetween and having axially-outer sides with respective end seals engaging said end faces;

a shaft having axially-spaced portions journaled in said wall bearings;

an eccentric portion mounted on said shaft having a peripheral wall with a circular radially-outer surface and having an opening extending therethrough with lengthwise bearing surfaces and widthwise bearing surfaces, said eccentric being journaled in said inner body coaxially therewith and having a variable offset distance from said shaft axis, said oifset varying a selective manner with each revolution of said eccentric and said shaft;

said eccentric having an intermediate shaft portion integral With said shaft end portions and having a square cross-section and being journaled in said opening, said intermediate shaft having a pair of radiallyouter bearing faces facing said inner bearing surfaces with a pair of anti-friction means disposed therebetween and having a compressive spring means disposed in said opening adjacent said intermediate shaft portion;

said gear means including a pair of gear units with each gear unit having a circular gear With internal teeth and a smaller ellipse gear with external teeth, said circular gear being fixedly connected to said inner body and said ellipse gear being fixedly connected to said outer body; and

said circular gear having a shoulder with a circular radially-inner bearing surface and said ellipse gear having a corresponding adjacent elliptical radiallyouter bearing surface in rolling contact with said inner bearing surface.

References Cited UNITED STATES PATENTS 1,617,863 2/1927 Planche 103130 1,636,486 7/1927 Planche 103-130 3,102,520 9/1963 Schlor 103-130 3,111,261 11/1963 Bentele et al 230- FOREIGN PATENTS 429,791 6/ 1935 Great Britain. 444,612 3/1936 Great Britain.

DONLEY J. STOCKING, Primary Examiner. WILBUR I. GOODLIN, Examiner, 

1. A ROTARY MACHINE FOR USE AS A COMBUSTION ENGINE, PUMP OR MOTOR COMPRISING: AN OUTER BODY WITH A LONGITUDINAL AXIS HAVING A PERIPHERAL WALL AND A PAIR OF AXIALLY-SPACED END WALLS FORMING A CAVITY THEREBETWEEN; AND INNER BODY DISPOSED IN SAID CAVITY FORMING A PLURALITY OF PERIPHERALLY-SPACED, VARIABLE-VOLUME CHAMBERS THEREBETWEEN AND HAVING AN AXIS ARRANGED PARALLEL TO SAID OUTER BODY AXIS; GEAR MEANS ENGAGING SAID INNER BODY AND SAID OUTER BODY FOR ROTATING SAID INNER BODY AXIS; AND SHAFT MEANS MOUNTED ON SAID OUTER BODY COAXIALLY THEREWITH A VARIABLE-OFFSET ECCENTRIC PORTION ON WHICH SAID INNER BODY IS JOURNALED COAXIALLY THEREWITH FOR REVOLVING SAID INNER BODY ABOUT SAID OUTER BODY AXIS AND FOR VARYING THE OFFSET DISTANCE BETWEEN SAID INNER BODY AXIS AND SAID OUTER BODY AXIS AND IN WHICH SAID OUTER BODY PERIPHERAL WALL HAS A RADIALLY 